Viruses as triggers of DNA rearrangements in host plants

Abstract

Andronic, L. 2012. Viruses as triggers of DNA rearrangements in host plants. Can. J. Plant Sci. 92: 1083–1091. Assessment of microsporogenesis in tomato (Lycopersicon esculentum, cultivars Fachel, Nistru and Prizior) infected with tomato aspermy virus or potato virus X and barley (Hordeum vulgare L., cultivars Galactic, Sonor, Unirea) infected with barley stripe mosaic virus showed deviations in the conjugation of homologous chromosomes and segregation of genetic material, expressed in the disruption of chromatin cohesion between homologous chromosomes. The evidence of meiotic division in targeted genotypes indicates the effect of viral infection on chiasmata number and position, promoting the redistribution of chiasmata. On the basis of cytological study, significant changes and the induction of additional exchanges offset by asynapsis were established in early diakinesis. Different parameters, determined at particular stages of meiosis, such as chromosome aberration and the mean percentage of abnormal pollen mother cells, served as cytogenetic evaluation of microsporogenesis in virus-infected tomato or barley cultivars. The study of meiotic stability in anaphase and telophase I and II revealed a significant increase in different types of abnormalities: elimination or/and lagging chromosomes, formation of chromosome and chromatid bridges with or without fragments. Reviewed examples provide data regarding genetic rearrangements in host plants as a response to viral infection.